A senior Chinese official yesterday attacked the planned iron ore joint venture between Rio Tinto and BHP Billiton, raising expectations that Beijing may use its antitrust law to try to scupper the “monopolistic” deal.

Chen Yanhai, head of the raw material department of China's ministry of industry and information technology, told state media that the joint venture “has an obvious colour of monopoly” and should be subject to China's anti-monopoly laws. “The joint venture is likely to have a big impact on the Chinese steel industry as China is the world's biggest iron ore importer,” he said.

BHP and Rio are the world's second and third-biggest producers of the metal that is steel's key ingredient. Together the companies supply 75 per cent of China's iron ore imports from their adjacent operations in Australia's Pilbara region.